The present invention relates generally to methods and devices for controlling processes, and more particularly to a method and device for controlling a process, in which an output variable, which depends on several influential variables acting on the process, is influenced by a correcting variable through a correcting element acting on the process in such fashion that it assumes the value of a predetermined controlling variable.
It is generally known that a process can be controlled in such fashion that the output variable of the process, in other words the regulated variable, is compared with a controlled variable and the regulating difference thus obtained is supplied to a regulating device, which generates a correcting variable at the output, with which the process is influenced by a correcting element. In addition to the correcting variable, a number of other influential variables also act on the process, with the relationship between the correcting variable and the influential variables on the one hand and the output variable of the process on the other hand being represented by graphs obtained by measuring the variables. These graphs, which in practice are almost always nonlinear, are usually not known exactly, however, and can change as the result of varying process conditions. This leads to the problem of adjusting the regulation of the process to changing process conditions to ensure that the regulating device always operates at the optimum working point.
The present invention is therefore directed to the problem of developing a method and a device for controlling a process in which the control is adjusted optimally to the actual process event, despite changing process conditions.